1. Field of the Invention
The present invention relates to a method for manufacturing a magnetic memory device and a structure for the same, and in particular, to a method for manufacturing a non-volatile magnetic memory device where inconsistency in the properties of memory cells can be reduced and a structure for the same.
2. Description of the Related Art
A TMR (tunneling magneto-resistance) element is located between a digit line and a bit line in a MRAM having a conventional structure. The TMR element is formed on a wiring layer and made of an insulating layer, as well as a free layer and a pin layer, which are provided so as to sandwich the insulating layer. It is noted that the TMR element is in some cases referred to as an MTJ (magnetic tunneling junction) element.
In the MRAM, an opening is formed in an interlayer insulating film and a metal layer is formed on the opening in accordance with, for example, a sputtering method, and after that, the surface is flattened in accordance with a CMP method, so that a plug connected to a wiring layer for connecting the wire and the TMR element in the lower layer is formed. Furthermore, a free layer, an insulating layer and a pin layer are laminated on the wiring layer in this order (JP 2000-277612, A).